This application is for funds to purchase an Olympus Fluoview 500 laser scanning confocal microscope under the auspices of the NCRR Shared Instrumentation Grant program. The Olympus FV500 is a laser scanning confocal microscope with up to 5 independent channels of detection, independently adjustable confocal pinholes, fully automated filter and mirror selection, and an intuitive and powerful software package. The three lasers requested, argon, red Helium-Neon and green Helium-Neon, will provide excitatory signals for most applications, with the expansion with additional lasers possible in the future. This application is supported by seven NIH funded investigators and one investigator funded from other sources. There is a tremendous need for an additional confocal microscope at Georgetown University Medical Center (GUMC) to complement the current instrument at the Lombardi Cancer Center and expand the capabilities of researchers on the campus. The current shared instrument is consistently subscribed to maximum capacity. The currently available instrument is adequate for most uses but many of the investigators in this application require further capabilities that will be provided by the requested instrument. This application is put forward by a group of investigators who require the use of confocal microscopy on a regular basis, who are familiar with its use, and many of whom have seen their research programs curtailed by the limited availability of the Lombardi cofocal. The new confocal will be housed and maintained in a Cell Biology imaging core, which will also house a transmission electron microscope, laser capture microdissection microscope and wide field light and fluorescent microscopes and associated accessories. The imaging core will be run by a technician who is to be named, and overseen by the PI in conjunction with appropriate oversight committees. The instrument will be available to all qualified investigators on a fee for service basis, with investigators in this application receiving priority. Funds to support the continued maintenance and operation of this instrument are to be provide by GUMC through the Office of the Dean of Research. Successful funding of this application will fill a clear need for expansion of confocal microscopy facilities on the GUMC campus and will allow for an increase in the quality and quantity of results derived from NIH funded research. [unreadable] [unreadable]